Acoustic bbceiving appakattjs



Nov. 13, 1923.

' C. A. CULVER ACOUSTIC RECEIVING APPARATUS Filed 06%. 23, 1919 5 Sheets-Sheet '1 w, IWVENTOR 3 flfoniey c. A. CULVER ACOUSTIC RECEIVING APPARATUS 5 Sheets-Sheet 3 Filed Oct. 25, 1919 [NI ENTOA Nov. 13, 1923. v

"' C. A. CULVER ACOUSTIC RECEIVING APPARATUS Filed Oct. 23, 1919 5 Sheets-Sheet 4 INVENTOA A/fomey New. Y3, 1923.

C. A. CULVER ACOUSTIC RECEIVING APPARATUS Filed Oct. 23. 1919 5 Sheets-Sheet 5 [NVENTOR i A liorney i atented Nov. 13, 1923.

CHARLES A. GULVER, OF BELOIT, WISCONSIN.

ACOUSTIC RECEIVING APPARATUS.

Application filed October 23, 1919. Serial No. 332,755.

To all whom it may concern 1 Be it known that I. CHARLES A. (VIM-tn.

a citizen of the United States. residing at new. in the county of Rock and State of l /isconsin, have invented certain new and useful improvements in Acoustic Receiving pparntuc, of .which the following is a specilic Lion.

invention relates to an improved apparatus for transmuting electrical impulses into audible sounds.

An object of the invention is the provision of improved audible means for indireceived signalling oscillations or other communications, particularly for detecting or indicating relatively faint signals. A. for her object is the provision of audible means arranged in coaction with suitable oe lhltion receiving circuits to selectively rednznped or undamped transmitted signal-.ing oscillations.

"llhe invention comprises selective impulse receiving means embodying selective means 1' r transmuting the received impulses into 2 dihle sounds. In accordance with the n we 'irelerred forms of the invention. air pi "e for radio communication, the inven tion comprises meuns for selectively tonne muting tne vibrations of an eleciro-mechanicaliy vibrated member into audible sounds. enacting with selertivelv receiving means. Finch vilcrntahle member is preferably 11 reed. of the free reed type. and provided with means for adjusting its effective length, or frequency.

Uther features and objects of the invention will be more fully understood from the following: description and the arcompanying, drawings, in which- Fig. 1 is a peispective view of. one form of my invention;

r 1g. 2 is a. similar view of another form of my invention;

limnxion of my invention;

Fig. is a diagram of a radio receiving as embodying my invention, El(l:i)l("l for selectively receiving damped signalling Waves;

i 5 is a diagram of a radio receiving .n embodying my invention, adapted tor selectively receiving undamped waves;

Fig. 6 if; a vertical, central sectional elevation of a preferred form of the invention; ;.own on an enlarged scale;

suitable sound emitting I, is a similar view of a further modi- Figs. 7 and S are respectively front end and top plan views of Fig. (3:

Fig. f) [H a detail [WI'HPQCUVP view of a laminated mire element shown in Fig. 6; and i Figure 1!) is a vertical elevation. on a Somewhat reduced sir-rile. of the base and standard, as \iMYtd from the left in Fig. 6, with the coils, reed. resonance chamber and other removable parts removed.

Referring to the forms of my invention shown in Figs 1, 2 and 3, the coil i, having thrtcrminuls :3, 3. arranged to recite electrical oscillations or other forms of signal impulses. In the form of the invention shown in Fig. l, the coil 1 is mounted on a pole l of the magnet 5, the same bring in electromagnetic relation with the reed (3. the end 7 ol' the reed (5 being suitably suspoiulod. as from the pole H of the magnet 53.

'lhe magnet 5 may be arranged to have its polo 8 disposed vertically above its poie 4-, and mounted on a brarket 9 having the support 10.

in acoustical relation with the reed 6 i arranged the remnant device ll. shown in tho form of a resonance chamber. of cylindrical r-ross-mwlion haviu; one end 12 closed and provided with the eou'ud receiving opening ill. The chamber ll is provided with means such as lb!- opeuing 14, preferably having the sound omitting menus shown us a binuurul bovinn our tips l6 and l7. 7

Thus, upon the reception oi signalling constructed and waves or other electrical impulses. the coil" 1. is em rgized. thereby electro-mechanicnlly vibrating the reed G in correspomlence with the intervals or modulations; of the received impulses.

The resonance chamber 11 serves. 0 ampliiy the vibrations or sounds emitted by line reed (l, and upon adjustuu-nt oi' the of length of the reed 25. I l

, with a similar resonance devi tying the transmuted signals. g 1

.transversely with respect to formed of two individual coils 18, 19' re In Fig. 2, the oscillation-sensitive coil is spectively mounted oh the poles 20, 21 of' the magnet..22. The magnet 22 maybe supported on a suitable bracket 23 having.

the base .24. The reed 25 is shown. suspended at-its lower end 26 on the bracket 23 hnd the free end 210i the reed 25Qarranged in vibratable relation with the poles 20, 21 of the-magnet 22. The individual coils 18, 19 are preferably wound in op-' posite direct-ions, whereby to produce 0p posing magnetic field's respect elyco-actmg with the opposing magnc poles 20,

2-1. The poles 20,21 are sho' n arranged in substantial alignment with/t e direction The operation of the form my inven tion shown 1n Fig. 2 is similar, to that of Fig. 1, and the reed 25 may provided Fig. 3 showsra modificatio similar to that shown" in Fig. 2, excepti g that the re arranged 35, is connectedto the primary coi-l 36'forniing. a tuning circuit with the adjustable condenser 37; said primary 36 is coupled with the secondary coil 38, one terminal of which is connected to the grid 39o! the vacuum oscillation tube 41) to .which is also apreferred form of unit mounting arrangement of the reed 41, oscillation-sensitive coils- 33, 33, and the adjustable amplifying, resonancechamber 42.-

Such fun'it arrangement comprises the supportin base 51 provided with the recesses 52 or the reception of suitable means for securing the base 51 to suitable sup-,, port. The base 51 is provided with the vertically extending standard 53, of. suitablenon-magnetic material, which may be integral' with the base 51. The reed 41 is mounted 'on the lug 54, extending shorizontally from the standard 53; the reed 41 is secured adjacent its end to the lug 54 by means of the sct-bolts'55 and strap 56. The reed 41 may be providedwith .the. amplitude-limiting means comprising for amplilation with the lug 58, extending vertically the set screw 57, mounted in threaded refrom the horizontal l'ug 54.

The oscillation-sensitive co1ls 33, 33 are respectively mounted in opposite relation on the laminated pole pieces 60, 61, r'espec-. tively clamped by means of the bolts 62,

90. 63, to the ends 64, 65, of'tlie permanent magneti68, see Fig. 7. Such bolts;62, 63, extend through 'the respective sets. of laminations 60, 61. and into the standard The standard 53 is recessed at .67 to provide 05 vthe ledge 68 for receiving and supporting the laminated poles 60, 61.. u

connected the condenser -11 and grid leak.

resistance 42. secondary 38 is connected to cathode filament 43,0f the-vacuum tube 40. The filament .43 is heated in the usual manner means of its battery '44,

The terminals of the secondary 38 are bridged by the adjustable condenser 45. The anode 46,- of the vacuum tube 40 is connected to" storage or other suitable ba't- The other terminal of "the' The poles 60, 61 are preferably formed of individually similarlycut laminm and in the arrangement shown 1 have foundrthc 14m form of lamina particularly indicated in. Figs. Band 9 to beadvantageous; As-showm each lamina 70 comprises a substantially rectangnlar body portion 71 and'an endportion 72, having a, face 73 extending transvcrscly and somewhat forwardly in the di recli on of length of the rectangular. body portion 71. 'lhe iforward side face 74'is preferably of extended effective length,- \vhercby the end portion 72 is of a general polygonal form, The resultant sets of [laminar 60, 61, as appears in' plan in I immediate adjacency oh the reed 41 and,

also provides for sufficient clearance-for the lation coil 1, coacting as above described" with a reed 6 anda transmuting chamber 12, shown diagi'annuatically as adjustable,

us more fully disclosed hereinafter.

In the system shown in Fig. 5, for re,

8, provide an intensified magnetic field in coils 33, 33 with suflicient space betweenthe respective parts to permit'ready in:

spection, adjustment and repair. (cry 47 and the terminals 2; 3, of the OSClldisposed the inlet opening 75 o'f'the reso- .nance chambr' 42. Theudjustment of the resonance chamber 42in the specific form shown fis attained bjntelescoping the mov- In Figs. 6 to 10 inclusive, I have indicated justment, the co-operating chamber port-ions able chamber portion 76 within the fixed chamber portion Z7. To attain precise ad.

76,.771a'reprovided with the intcrmeshing threads 18, 79. The resonance chamber 42 is shown of the closed type. The manipulation of the movable chamber portion 76' is facilitated by milling its outer rixn'as indieated at 80 The sound emitting opening 81 is located at any suitable position, and may be confliljild. With a binaural, as indicated in Fig. l, aforesaid.

The resonance chamber 42 is shown remo "ably mounted on the standard 53. by means oi the arm 82, extending (IOWHV- ardly of the chamber portion 77', and provided with the reduced extension 83 adapted to extend through a suitable opening in the lug 54, such extension 83 being threaded at its end 84- to receive the tightening nut 85.

. The binding posts-86, are respectively mounted on thedisks 88, 89 of insulation, secured respectively to the standard 5 3 by the nut screws 90. The binding posts 86, 87

receive the terminals of the oscillation coils 33 and the leads of the receiving circuit.

arranged as hereinabove set forth.

U on receivin undam )ed Waves the reed P e l 41 and the chamber 42 are respectively 2l(l-- 5 justed to the particular beat tone freqnenry" of theuvaves, whereby the receiving system selectively responds solely to the impulses desired to be received. In receiving spark signals,'the reed 41 and the resonant chamber 42 are respectively adjusted -to the spark frequency of the transmitting station. w

Accordingly, the system receives selectively through a plurality of adjustable selective means. The system is advantageous also in eliminating static or stray radiations. Tthe reed is formed with a low damping factor relative to the damping factor of the diaphragm of an ordinary telephone re-' eeiver, whereby the reed is relatively highly responsive solely to impulses of Waves which are consonant with the natural period of vibration ol' the reed.

\Vhereas l have described my invention by reference to specific forms thereofiit will be understood that many changes and modifications may be made without depart-- ing from the spirit of the invention as de fined by the appended claims,

I claim:

l; In a signalling device; an electromagnetic monotone system comprising an i-lectro-magnetically vibrated reed sup-ported at one end, in order to be fully responsive to vibrations of a single frequency, an electro. magnet for vibrating said reed at one sideof said reed, a resonance chamber normally brating said reed at one side of said reed a resonance chamber normally in resonance with said reed vibrations'at the other side oi said reed for amplifying the intensity of sounds produced by said reed, means for varying the period of resonanre of said resonance chamber, and aural means for the reception; of said'sound waves.

In testimony whereof} allix my signature CHARLES A. l/ LVER 

